navy. we explain what it is here and what it is doing. >> if you are looked up lately, you may have spotted this in the clouds or loving or baltimore's harbor. >> i have been seeing it all week. >> reporter: a u.s. navy blimp, 2'0"0 long is flying own baltimore. >> we are talking about it. >> i was coming down 95 and i'm like, what is with that blimp. >> the u.s. navy research laboratory is saying it is a government airship, conducting area mapping. the blimp is mapping washington, d.c. and bwi. >> and the blimp is propelled by two 1 achy horse pow -- 80- horsepower engines. and the blimp has started twitter discussions. >> usually when they have a football game or something, you see a blimp, good year, metlife, or something like that. >> reporter: but this -- will not be up for longer. after october 5th it is flying away. when the mission is complete, pilots will fly it to a base in new jersey. >> wjz eyewitness news. >>> the orioles are holding the red sox. and the division champs came to